Ge Energy Power Conversion Technology Gmbh

Converteam UK Ltd.

Richard Ian Stephens

Lihua Hu

Martin Samuel Butcher

Andrew Graham Chamberlain

Francois Cretollier

John Charles Flint

Anthony John Howard Wilkins

A converter control arrangement () for regulating the output current of a dc source power converter () comprises a current regulator () for regulating the output current based on a comparison of an output current value (I) of the dc source power converter () with a desired target current value (I). When the output voltage value (V) of the dc source power converter () is within a normal operating voltage range between minimum and maximum voltage values (V, V) defined with respect to a voltage reference value (V) of the dc source power converter (), the converter control arrangement () controls the target current value (I) so that it is equal to a desired reference current value (I). When the output voltage value (V) is outside the normal operating voltage range, which typically indicates a fault condition, the converter control arrangement () modulates the reference current value (I) to provide a target current value (I) that is less than the reference current value (I).

Control arrangement and method for regulating the output current of a dc source power converter connected to a multi-source dc system

A data fusion architecture with a plurality of sensors, optionally position measuring equipment (PMEs), is described. Each sensor supplies measurement data x, x. . . xand is associated with accuracy data H, H. . . Hindicative of the accuracy of the supplied measurement data. Sub-processing units derives first estimates sf, sf. . . sfand second estimates Hn, Hn. . . Hnof the variability of the measurement data supplied by the respective sensor. The first estimates are derived by processing the measurement data x, x. . . xand the second estimates are derived by processing the accuracy data H, H. . . H. The first and second estimates are combined in a multiplier to derive overall estimates &#x3c3;, &#x3c3;. . . &#x3c3;of the variability of the measurement data supplied by the respective sensor. Data fusion means such as a Kalman filter combines the measurement data supplied by each sensor and the overall estimates &#x3c3;, &#x3c3;. . . &#x3c3;for each sensor.

Data fusion architecture

A method of operating a dual fed system is described where power is supplied to a electrical load from first and second ac busbars at a ratio that achieves a desired level of exhaust emissions such as nitrogen oxides (NO), carbon dioxide (CO) and other pollutants produced by the prime movers associated with generators. Preferably, the method may be used to operate a dual fed marine propulsion system wherein the electrical load is a thruster. Operating a dual fed marine propulsion system using the method of the present invention makes it possible to optimize thrust allocation between thrusters in a way that is similar to that used in conventional dynamic positioning (DP) systems and then share or allocate the required power between generators to minimize exhaust emissions.

Methods of operating dual fed systems

Dynamic positioning systems and methods for controlling thrusters of a vessel. A dynamic positioning system includes a controller configured to predict position and heading of the vessel and efficiently control the the thrusters based on the predicted position and heading.

Dynamic positioning systems and methods

The present invention provides an improved architecture for integrating an inertial navigation system (INS) into a dynamic positioning (DP) system for a vessel. The architecture includes an INS unit and a DP system having a Kalman filter or other algorithm for combining data supplied by a plurality of position measuring equipment (PME) and the INS unit to derive an estimate of the position or speed of the vessel. A switch array and a switch array controller are also provided. These may optionally form a part of the DP system. The switch array is operable under the control of the switch array controller to supply data supplied by one or more of the plurality of position measuring equipment to the INS unit for the purposes of correcting drift. The selection of which of the one or more PME is/are to be combined with the INS unit is made automatically, in real time, to dynamically optimise the DP system.

Dynamic positioning architecture

A method of estimating the environmental force acting on a supported jack-up vessel is described. The vessel is positioned in a force determination position and the strain on at least one support leg of the jack-up vessel is measured while a first thrust is applied to the vessel. A second thrust is applied to the vessel while the vessel is maintained in the force determination position. The variation in the strain in the at least one support leg is monitored as the second thrust is applied and the strain is used to calculate an estimate of the environmental force acting on the vessel. The method allows a dynamic positioning (DP) system of the jack-up vessel to determine a suitable thrust to apply to the vessel as the support legs of the vessel are raised. By applying this suitable thrust the position of the vessel can be maintained when the vessel transitions from being supported by the support legs to being supported by water.

Method of estimating the environmental force acting on a supported jack-up vessel

The present invention provides a method of controlling the position of a spread moored marine vessel (). In particular, the method of the present invention substantially maintains the position of a spread moored vessel () in, or on the boundary of a target area () using thruster assistance. This is done by monitoring the position of the vessel and when the vessel () is positioned outside of the target area () applying a position correcting thrust () to the vessel () in the direction of an aim position located on the boundary of the target area () and when the vessel () is positioned within the target area () reducing the position correcting thrust () applied to the vessel () or maintaining the position correcting thrust () applied to the vessel () at zero. The present invention may also apply a damping thrust () to the vessel () in order to damp the positional variation of the vessel (). The present invention also provides a thruster assisted mooring system for a spread moored vessel () operating according to the method of the present invention.

Method of controlling the position of moored marine vessels

Dynamic positioning of a vesselconnected to the seafloorby a riserutilizes a measurement of riserbottom angle combined with a measurement of vesselvelocity, optionally obtained from a Doppler log. These two signals are combined to produce a single position estimate using an algorithm such as a Kalman filter. Using riser bottom angle only would result in an unstable control system, since the bottom angle lags the vessel motion by a considerable amount and the relationship is non-linear. Using the velocity measurement alone would result in a slow drift of position. The combination of the two eliminates the disadvantages of the individual measurements.

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Warwickshire, United Kingdom

Richard Ian Stephens